Mineral wool product

ABSTRACT

The invention relates to a mineral wool product comprising mineral fibers that is marked with an UV or IR active substance and can therefore be identified under exposure to suitable radiation.

This application is a Continuation of International Application No.PCT/EP2010/055415, filed Apr. 23, 2010, which claims the benefit ofGerman Application No. 102009018688.3, filed Apr. 23, 2009, the entiredisclosures of which are hereby incorporated by reference.

This invention relates to a mineral wool product comprising mineralfibers, particularly mineral wool adapted for use as a building materialin buildings and/or civil engineering, particularly as thermal and/oracoustic insulation, and more particularly to such a product whoseprovenance may be easily traced.

The term mineral fiber is intended to include stone wool fibers, glasswool fibers, slag fibers, and ceramic fibers.

Mineral wool products are used in various forms and applicationsincluding:

Forms:

-   -   loose, untreated mineral wool (for example, blowing wool)    -   loose mineral wool with uncured binding agent (for example,        blowing wool)    -   needled mineral wool products without a binding agent, but        comprising a lubricant (e.g. a lubricating oil)    -   mineral wool mats, mineral wool panels and mineral wool moulded        parts, provided with a cured or uncured binding agent    -   composite bodies with a mineral wool layer, for example        composite panels with a layer of bonded wood wool and a layer of        mineral wool comprising a cured binding agent

Applications:

-   -   thermal and/or acoustic insulation in buildings and civil        engineering    -   thermal and/or acoustic insulation of: electrical appliances        such as refrigerators; cars; industrial installations and their        parts    -   growth base for plants        Typical properties for such mineral wool products may include:    -   the mineral fibers being short (rather than being continuous,        long fibers) and thin (average diameter generally <10 μm)    -   such products made from mineral fibers have high open porosity,        generally >70% by volume    -   the amount of binding agent or lubricant agent proportion (if        present) is usually between 0% and 12% by weight with respect to        the mineral wool product    -   the binding agent (if present) may comprise phenol formaldehyde        or a binding agent that is free from phenol formaldehyde

In accordance with the invention, the amount of the binding agent orlubricant (if present) may be, for example, between 0.01 and 10% byweight or between 0.1 and 8% by weight with respect to the mineral woolproduct. In accordance with one specific example, the amount of bindingagent or lubricant is between 0.2 and 5% by weight.

The binding agent may be used to provide markings to the mineral woolproducts. To do this, the binding agent may be purposefully discolored,for example with hot air, electrical heaters or laser beams (EP 1 108694 B1; DE 3 229 601 A1; DE 29 822 362 U1).

One aspect of the invention is based on providing mineral wool productswith a marking in a non-destructive way, particularly without requiringany particular precautions during manufacturing. A further aspect of theinvention is based upon providing mineral wool products with a markingwhich does not detract from the appearance of the product and/or can beeasily detected or revealed, particularly when the product has beeninstalled.

The invention is based on the knowledge that these objectives can beachieved in a completely different way, i.e. by applying components tothe mineral wool product that do not detrimentally physically change themineral wool product as such, and are neither optically nor physicallyvisible, but become visible when ultra-violet (UV) or infra-red (IR)radiation is directed at them. UV radiation is invisible to humans andhas a wavelength of approximately 10 to 400 nm, while IR radiationcovers the wavelength range of greater than 780 nm up to approximately1300 nm.

The specified components are UV or IR active substances in which thecoloring can only be seen with the naked eye under ambient conditionswhen irradiated with a source of UV or IR radiation. Hence, for example,a UV light source stimulates the UV active substances in the mineralwool product to produce a visible fluorescence. The specified componentsform a type of optical converter, which for example, converts incidentUV radiation of a specific wavelength into visible light with a longerwavelength.

Generally, the wavelength of the emitted light is greater than that ofthe stimulating light. For IR radiation with wavelengths >780 nm, thisgenerally means that direct conversion in to visible light withwavelengths between 400 and 780 nm is not possible.

Some crystalline luminescent materials are visibly fluorescent if theyare stimulated with blue or ultraviolet light. Through a specificcrystal doping, however, it is possible to suppress such spontaneousemission, and the stimulating energy then remains stored. IR radiationthen releases the stored energy, allowing emissions in the range ofvisible light. Under the influence of IR radiation, the IR activecomponents, or alternatively the respective zones/areas with IR activecomponents, illuminate. Corresponding IR active components can be usedas such or they may be already charged (pre-stored). In the first case,they must be charged with UV radiation (activated) before their actualuse.

Mineral wool product according to preferred embodiments of the inventioncan not be identified as such (from the outside) or be differentiatedfrom a conventional mineral wool product under normal, ambientconditions, that is to say that the marking remains “invisible” undernormal conditions. This may be important for optical reasons, forexample for mineral wool elements that are used in interior finishingwith visible surfaces.

The latently effective colorants (UV or IR active substances), however,make it possible to identify the product at any time if need be, notablyby subjecting the product to a level of incident UV or IR radiationwhich reveals the marking. It is even possible to charge the IRindicators by means of UV radiation, for example, only when theirpresence is to be checked.

This results in the following important advantages over mineral woolproducts with known types of marking of the type previously specified:

-   the binding agent or the lubricant remain completely effective-   the physical properties of the product remain unchanged or    substantially unchanged-   the optical properties or visual appearance of the product can be    chosen freely independent of any possible marking

In one of its aspects, the invention relates to a mineral wool productthat comprises at least one UV or IR active component and, optionally, abinding agent (which may be formaldehyde-based or formaldehyde-free).

When present, any suitable binder may be used including formaldehydecontaining binders (for example phenol formaldehyde binders) and binderswhich are formaldehyde free. The term “formaldehyde free” in relation tobinders is intended to indicate that the constituents making up thebinder do not comprise formaldehyde, particularly free formaldehyde,and\or do not release formaldehyde in ordinary usage. Examples ofbinding agents that do not contain formaldehyde are binding agents thatare obtained from an amine component and a sugar, particularly areducing sugar, which may comprise melanoidins or glycosylamines.Specific examples of formaldehyde-free binding agents that can be usedaccording to the invention are described in WO 2007/014236. Thesespecific examples include binders based on a sugar, particularly areducing sugar (for example dextrose), an acid or an acid precursor (forexample triammonium citrate) and a source of nitrogen.

The UV or IR active component may be distributed through the mineralfiber product for example homogenously amongst the mineral fibers. Forexample, the coloring component can be admixed to a carrier medium, forexample a binder and added to the fiber flow in the conventional waywhen manufacturing the mineral wool product and thereby distributedhomogenously through the product. Alternatively, the UV or IR activecomponent may be added to a dispersion medium or a suitable solvent orsprayed onto the mineral wool product in a pure form. The UV or IRactive component is preferably applied to the mineral fibers beforecuring of any binder of the mineral fiber product.

The UV or IR active component may include other substances such as, forexample, ethidiumbromide, amino acids like tryptophan, tyrosine, andphenylalanine, or peptides and proteins.

The at least one UV or IR active component (also called an indicatorsubstance) may be applied separately to a so-called fiber cloud (e.g.immediately after manufacture of fibers from a melt), or appliedseparately to an already manufactured primary fleece or secondaryfleece, for example spayed on. In like manner, the UV or IR activesubstance can also be applied to a finished fiber product, especially ifa specific area on the surface of the product is to be marked.

If the indicator substance is distributed throughout the mineral fiberproduct, for example via a homogenous distribution of the indicatorsubstance in the product, this may be seen under UV or alternatively IRlight as an essentially uniform color, for example a green or red color.

The indicator substance may allow products from different plants ordifferent years of production to be readily identified, for example byusing a particular indicator substance as an indication of year ofmanufacture and/or site of manufacture.

This type of marking/identification can, of course, also be achievedwith only partial distribution of the indicator substance. Withtargeted, partial application, for example on a section of the surface,it is possible to form appropriately colored zones of any shape as amarking. For example, company names, product names, trademarks,pictures, standards, manufacturing data, product characteristics, etc.can be shown specifically. The locally applied UV and IR activecomponents for such markings, applied on a surface area, may be coatedor sprayed on, for example, or applied as a suspension by means ofstamps.

When the marking/identification is applied only to a section of thesurface of a product, subsequent examination of that particular surfaceis required to determine the presence or absence of themarking/identification. One advantage of distributing the indicatorsubstance throughout the mineral fiber product is that examination ofany portion of the mineral fiber product may be used to reveal thepresence or absence of the marking/identification. For example, wherethe mineral wool product is installed in a cavity wall, any easilyaccessible portion of the mineral wool product may be examined in situ(without dismantling the wall to reveal an entire surface of the mineralwool product) or a sample of the mineral wool product may be removed forexamination. Similarly, distribution of the indicator substancethroughout the mineral fiber product is particularly advantageous whereit not feasible to apply a marking/identification to a surface of themineral wool product, for example for blowing wool.

The at least one UV active component may comprise at least one compoundfrom the group consisting of: flavonic acid, 4,4′ Distyryl-biphenyls,stilbenes, pyrazolines, coumarin, dihydroquinolines, naphthalene acidimides, benzoaxazole, benzioxazole compounds, riboflavin, quinine,chlorogenic acid, quinoline yellow, and derivatives thereof.

The indicator substance may be used as a powder or in a liquidpreparation, for example in aqueous solution or as a viscous liquid.

The at least one IR active component may comprise a compound selectedfrom the group consisting of doped (not radioactive) strontium sulphide,doped zinc sulphide, yttrium compounds, ytterbium compounds and erbiumcompounds. The strontium sulphide may be doped with europium and/orsamarium; the zinc sulphide may be doped with copper and/or lead.

For example, areas that contain yttrium-ytterbium-erbium compoundsappear green under IR radiation.

Many IR active components can also be used as UV active substancesbecause they have their own UV fluorescence.

The percentage by weight of the UV or IR active component, based on thetotal mineral wool product or alternatively the mineral wool component(for composite structural elements), may be less than 1.0% by weight.For example, the percentage by weight of the UV or IR active componentbased on the entire mineral wool product or alternatively the mineralwool proportion may be less than 0.5% by weight or less than 0.2% byweight.

If one relates the proportion of the UV or IR active component to themass of the binding agent or lubricant, then the amount is usually from0.1% to 5% by weight. The proportion of the UV or IR active componentbased on the mass of binding agent or lubricant may be 0.2% to 3% byweight or 0.2% to 1.5% by weight.

Water soluble UV or IR active components have the advantage that theyare easy to apply in a liquid or viscous preparation, for example theymay be sprayed on or injected.

The mineral wool product may be provided with one or more of thespecified coloring components, for example in order to make one or morecolors recognisable under the respective light. For some applications itis sufficient to use the light active components only in specificsections of the product, for example on one surface or in an area thatis close to the surface. Due to the high open porosity of the fiberproducts, it is also possible to color identify zones that are below thesurface.

Preferred or alternative characteristics are defined in the dependentclaims. The following examples, from which characteristics may be usedindividually or in any combination in relation to the invention, shouldnot be considered as limiting.

EXAMPLE 1

Stone wool fibers are spun from a stream of mineral fiber melt using aseries of external spinning wheels. In the flow of fibers created as thefibers leave the spinning wheels and are carried in a forced air streamtowards a collecting apparatus, a mixture of phenol formaldehyde binder(3% by weight based on the finished product) and stilbene (0.3% byweight based on the finished product) is injected (sprayed)homogeneously. A primary fleece is then formed from the collected fibersin the usual way and a secondary fleece is then formed by folding theprimary fleece, ultimately resulting, once passed through an oven tocure the phenol formaldehyde binding agent, in a mineral wool matt witha density of 40 kg/m³ adapted for insulating between rafters.

Even at the end of the life of the product, for example 50 years later,for example when demolishing a house insulated using the product, it ispossible by means of UV irradiation to color activate the stilbenecomponent and, based on the coloring, to identify for example the yearof manufacture and/or the manufacturer and/or the manufacturer's plant.

EXAMPLE 2

A mixture of binding agent (for example a phenol formaldehyde binder)and zinc sulphide doped with copper and lead, is applied to one surfaceof a conventionally manufactured finished mineral fiber panel having adensity of 150 kg/m³. This is carried out by spraying the indicatorsubstance while using a mask to apply an identifier in the form of abarcode on the surface. The barcode may contain information such as themanufacturer, type of product, product properties, year of production,etc. The area where the identifier is applied is subsequently charged bymeans of UV radiation. The identifier is optically invisible to thenaked eye under normal ambient lighting conditions, but can be renderedvisible at any time under IR radiation.

1. Mineral wool insulation product comprising at least one UV or IRactive component.
 2. Mineral wool product according to claim 1, wherebythe UV or IR active component is distributed through the mineral woolproduct, particularly homogeneously through the mineral fibers. 3.Mineral wool product according to claim 1, whereby the UV or IR activecomponent is arranged in at least one locally limited section. 4.Mineral wool product according to claim 1, whereby the UV or IR activecomponent is arranged at least one section of a surface of the product.5. Mineral wool product according to claim 1, whereby the UV or IRactive component is arranged on at least one section of a surface of theproduct in the form of an identifier.
 6. Mineral wool product accordingto claim 1, whereby the UV or IR active component is present with acarrier medium in a mixture.
 7. Mineral wool product according to claim1, whereby the UV or IR active component is present with a binding agentor a lubricant in a mixture.
 8. Mineral wool product in accordance withclaim 1, whereby the mineral wool product comprises at least one UVactive component selected from the group consisting of: flavonic acid,4,4′ Distyryl-biphenyls, stilbenes, pyrazolines, coumarin,dihydroquinolines, naphthalene acid imides, benzoaxazole, benzioxazolecompounds, riboflavin, quinine, chlorogenic acid, quinoline yellow, andderivatives thereof.
 9. Mineral wool product in accordance with claim 1,whereby the mineral wool product comprises at least one IR activecomponent selected from the group consisting of doped strontiumsulphide, doped zinc sulphide, yttrium compounds, ytterbium compoundsand erbium compounds.
 10. Mineral wool product in accordance with claim1, whereby the amount of UV or IR active component in the mineral woolproduct is less than 1% by weight based on the total weight of themineral wool product.
 11. Mineral wool product according to claim 1,whereby the UV or IR active component is water soluble.
 12. Mineral woolproduct according to claim 1, whereby the UV or IR active component ismonochromatically fluorescent.
 13. Use of at least one UV or IR activecomponent as a marker or identifier in a mineral wool insulationproduct.
 14. Use of at least one UV or IR active component in accordancewith claim 13, in which the component is distributed throughout themineral wool product.
 15. Use of at least one UV or IR active componentin accordance with claim 13, in which the component is provided at anexternal surface of the mineral wool product.